1. Field of the Invention
The technique disclosed in this specification relates to a storage controller and its control method, and more particularly to a storage system in a remote copy environment in a computer system having a plurality of storage controllers.
2. Description of the Related Art
As the amount of data has increased explosively, the number of host computers within a computer system and the capacities of storage systems tend to increase.
Additionally, as businesses depend more on information processing systems and the amount of damage caused by lost of data increases to an enormous level, the importance of disaster recovery of the data increase more and more.
A typical fabrication example of disaster recovery is a remote copy configuration. For example, JP-A-HEI-11-85408 discloses the techniques by which data issued by a host computer is received by a storage system, the storage system writes the data therein, and transfers the data to a different storage system installed at a physically remote location to make it store the data.